Duct Sealing: One Way to Improve Energy Efficiency in Commercial Settings

In your commercial facility, leaky ductwork can account for significant amounts of lost energy and money every year. By adding duct sealing to your regular HVAC preventive maintenance routines, you’ll boost heating and cooling system performance, conserve substantial amounts of energy and decrease the amount you spend on indoor comfort at your business location.

The importance of ducts and duct sealing

The ductwork in your heating and cooling system is the large network of pipes that carries heated or cooled air from your furnace, heat pump, air conditioner or boiler. HVAC efficiency relies on moving conditioned air without obstruction and without leakage anywhere within the ductwork system. In a commercial facility, duct networks can be very long and complex. Over time, sections can come apart or seals can break. Animals or rodents can cause damage. Accidents can damage ductwork, or simple age and wear can create problems. Duct sealing will ensure that these broken seals, loose sections and other problems are properly repaired and that heated or cooled air cannot escape unused.

Duct sealing and testing

Your HVAC contractor will commonly start by inspecting your ductwork system from end to end and testing the ductwork for leaks. Once hidden leaks are located, your technician will know where to concentrate his duct-sealing efforts. The major portion of duct sealing involves making sure the ducts are effectively sealed at all connections. This usually involves applying mastic or metal tape to the locations where ductwork sections connect together. Mastic is a specialized flexible sealant that is applied in layers about as thick as a nickel coin. Mastic does not harden or become brittle, which means it maintains its seal. Metal tape has sturdy and long-lasting adhesive that won’t fail over time. Ironically, standard duct tape is not recommended for sealing ductwork. The adhesive on duct tape can dry out and fail, causing the tape to fall away and reopen any gaps or leaks.

The technician should also:

• Check all sections to make sure they fit together tightly, with particular attention to elbows and branches.
• Repair damage, reconnect loose sections, straighten out tangled ducts and replace missing sections.
• Mechanically seal connections with sheet-metal screws or other appropriate fasteners.
• Evaluate the supply and return air balance of the network.
• Assess ductwork size and make recommendations for changes.
• Check registers and vents for proper connections.
• Insulate the ductwork to prevent energy loss through the material of the ductwork itself.
• Measure air flow after maintenance to ensure correct flow of air
• Test air flow to ensure no carbon monoxide leaks.

Benefits of duct sealing

A well-sealed ductwork system will provide benefits such as:

• Decreased facility energy bills: Leaky ducts can lose 20 percent or more of the conditioned air flowing through them. When this loss is stopped, more of the air you pay for will be used, and you’ll spend less making up for heated or cooled air that is wasted.
• Improved indoor comfort: Sealed ducts prevent leaks that cause inconsistent heating and cooling. A well-sealed duct system distributes heated and cooled air more evenly and efficiently.
• Better indoor air quality: A sealed ductwork system is less likely to return dust and other airborne particles to your indoor environment. Aggravating fumes and vapors will be unable to seep into the ductwork and be circulated throughout your building.
• Less waste: Duct sealing cuts down on energy waste, which benefits your local environment and reduces demand on local utility companies.
• Better safety: A well-sealed ductwork system is less likely to allow harmful substances such as carbon monoxide or other exhaust gases back into your facility.

Our goal is to help educate our customers about Plumbing, HVACR, Fire Protection and Alarm Systems in Mechanical, Commercial, and Residential settings. For more information on duct sealing and how it can improve the energy efficiency of your commercial facility, or to view projects we’ve worked on, visit our website!